Device for accurately positioning a body suspended from cables

ABSTRACT

A body is suspended from a trolley solely by hoisting cables or by a combination of hoisting cables and positioning wires. In the case when only hoisting cables are employed, they pass on drums joined together and so operated to raise and lower the load, the hoisting cables passing on sheaves and being connected to the trolley by support members which are pivotable to compensate for load differences in the cables, the sheaves also being pivotable on the trolley to compensate for elongation differences in the cable. In the case when positioning cables are utilized, the latter are connected to a driving drum over pivotable sheaves to compensate for elongation differences in the cables, the ends of the hoisting cables being connected to the trolley by displaceable support members which compensate for load differences in the hoisting cables.

United States Patent [191 Hupkes DEVICE FOR ACCURATELY POSITIONING ABODY SUSPENDED FROM CABLES [75] Inventor: Leonard Hupkes, Heemstede,

Netherlands [73] Assignee: Werf Conrad & Stork lHiisch N.V. [22] Filed:Jan. 27, 1972 [21] Appl. No.: 221,361

[30] Foreign Application Priority Data 212/83, 11; 254/144, 173;214/14.15; 244/81 SF; 294/81 SF, 67 R [56] References Cited UNITEDSTATES PATENTS 3,161,309 12/1964 Baudhuin et al. 294/81 SF 3,179,2594/1965 McLean 212/126 3,273,860 9/1966 Weisenbach 254/173 3,510,1075/1970 Fidler 254/173 FOREIGN PATENTS OR APPLICATIONS 742,094 9/1966Canada 254/173 [4.51 Oct. 22, 1974 Primary Examiner-Evon C. BlunkAssistant ExaminerHadd Lane Attorney, Agent, or Firm-Eric l-l. Waters 57] ABSTRACT A body is suspended from a trolley solely by hoisting cablesor by a combination of hoisting cables and positioning wires. in thecase when only hoisting cables are employed, they pass on drums joinedtogether and so operated to raise and lower the load, the hoistingcables passing on sheaves and being connected to the trolley by supportmembers which are pivotable to compensate for load differences in thecables, the sheaves also being pivotable on the trolley to compensatefor elongation differences in the cable. In the case when positioningcables are utilized, the latter are connected to a driving drum overpivotable sheaves to compensate for elongation differences in thecables,

the ends of the hoisting cables being connected to the 2 Claims, 5Drawing Figures DEVICE FOR ACCURATELY POSITIONING A BODY SUSPENDED FROMCABLES BACKGROUND OF THE INVENTION a. Field of the Invention The presentinvention relates to a device for accurately positioning a bodysuspended via an engaging means from one or more cables of a hoistingdevice in which at least two cables or wires, which are in communicationwith the body or the engaging means, are guided each at an angle to thevertical, and not parallel to each other, to a drum which may be driven.b. Prior Art A device of this type is disclosed in Applicants earlierApplication Ser. No. 158,539 filed Aug. 3, 1974. In said device, specialpositioning wires are passed to drums which may be driven, said drumsbeing coupled in such a manner that a rotation of the drums relative toeach other will effect a change in the driving moment of one of thedrums. It has appeared that this device permits a displacement of thecontainer due to elongation in the positioning cables, which, inpractice, may become excessive.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide a device of the aforementioned type which does not have thedisadvantage associated therewith. r

In accordance with the invention, a device is provided for accuratelypositioning a body suspended from cables of a hoisting device, saiddevice being characterized' in that means are provided to prevent achange in the positions of the drums for the wires or cables relative toeach other, at least in the sense that one drum will unwind relative tothe other drum, irrespective of the amount of stress in the wires, andfurther means are provided to compensate for the differences inelongation in the wires and/or the cables. The inclined wires or cablesmay consist of special positioning wires or they may be formed by thehoisting cables, in the first case one or more separate drums for thepositioning wires are provided.

The means for preventing a change in the positions of the drums relativeto each other, consists preferably of mechanical coupling means for thedrums or of means for uniting the drums as one single drum around whichthe two wires are passed in the same sense.

The means for preventing a change of the positions of the drums relativeto each other may also consist of an analog or digital control of thedriving means of the drums.

In a device with separate positioning wires, the means for compensatingfor the differences in elongation of the wires preferably comprisesmovably mounted sheaves, over which the positioning wires are passed tothe drums and a device which can transform a difference between thestresses in the wires into such a relative movement of said guidingsheaves that the difference in elongation will be compensated.

In the embodiment in which the driving means of the drums of the wiresor cables are controlled by analog or digital means, the means forcompensating for the differences in elongation of the wires or cablesmay also consist of means controlling the driving means of the drums sothat the drum around which the wire or cable subjected to the greateststress is passed will wind up relative to the other drum.

If wind forces act on a body suspended from hoisting cables in a deviceas described above, then it is not possible that a horizontaldisplacement of the body will occur, inasmuch as the positioning wiresor the hoisting cables will prevent such a displacement. In doing so,one of the positioning wires or hoisting cables will be subjected to ahigher load and the other wire or cable will be subjected to a lowerload, as a consequence of which the wire or cable with the higher loadwill elongate, however, said elongation will be compensated in one ofthe ways described above, so that also a horizontal displacementresulting from said elongation is prevented.

Thus, a body suspended by cables of a hoisting device may be accuratelypositioned as to the position where the body is to be deposited.Accurate positioning, however, requires also that the body will comedown in the correct position. With a container this means with itssurface absolutely horizontal. This will be the case if the center ofgravity of the container lies on the vertical central axis of thecontainer. This is often not the case, so that as a consequence of theunequal loads of the hoisting cable which then occur, the cables willnot stretch to the same extent and the container will hang aslant.

In order to prevent this, both in the device with positioning wires andwithout same, in accordance with the invention, the cables from whichthe body is suspended are connected with a system for measuring thediffer ences in load between said cables, while the points where saidcables engage the hoisting device are engaged in movably mountedsupports, and a mechanism is present to move said supports in responseto the measured differences in load so that the difference in elongationof the cables will be compensated Inasmuch as the elongation of a cableor a wire apart from the load is also dependent from the length of thecable or wire, a device is present in accordance with the invention,which can control the measuring system for measuring the differences inload between the hoisting cables and/or the means for compensating thedifferences in elongation in the positioning wires in dependency on thelength of the cable between the body and the hoisting device.

The invention will now be described in greater detail, with reference tothe accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic side view of afirst embodiment of the present invention with separate positioningwires;

FIG. 2 is a schematic view, on enlarged scale, of an alternativeembodiment of a means for compensating the differences in elongation inthe positioning wires;

FIG. 3 is a perspective view of a second embodiment of the presentinvention, without separate positioning wires;

FIG. 4 is a perspective view of a means for compensating the differencesin elongation in the hoisting cables illustrated in FIG. 3; and

FIG. 5 shows in perspective a means for guiding the hoisting cablesillustrated in FIG. 3 by means of a spring.

DETAILED DESCRIPTION Regarding FIG. 1, therein is seen part of a girder1 of a container bridge, along which a trolley 2 may travel on wheels 3.A hoisting drum 4 is mounted on the trolley, and hoisting cables 5 ofthe drum extend to sheaves 6 on a lifting frame of a container. Thehoisting cables 5 extend around the sheaves 6 and are fixed at supports8 on the trolley 2. Measuring systems are built in the support 8 tomeasure the differences in load in the hoisting cables and control amechanism (not shown) to move the supports 8 in a manner so that thedifference in elongation of the hoisting cables will be compensated,whereby the lifting frame 7 and the load 9 suspended therefrom willremain absolutely horizontal. This movement may be continuous orstepwise. It is also possible to adapt the movement of the supports 8 ofthe hoisting cables 5 to a secondary action, such as an offset positionof the center of gravity of the load 9 or a difference in deflection ofthe girder 1.

Additionally, a drivable drum 10 is mounted on the trolley 2, andpositioning wires 11 extend around drum l0 and are guided on sheaves 12to the lifting frame 7 of the container. The drum 10 is subjected to asuitable constant torque so that the wires 11 will be kept continuouslytensioned, both during standstill and during the hoisting and loweringof the load 9. The sheaves 12 are mounted on hinged rods 13 which areconnected to each other by a rod 14. Measuring devices 15 are mounted onrod 14 to provide a signal which is transmitted to a control device 16which can move the rod 14 to the left or to the right. Thus, if, forexample, a wind force acts on the right-hand lateral face of thecontainer 9 (as shown in the drawing), the positioning wire 11 at theextreme right will be subjected to a higher load than the positioningwire 11 at the extreme left side. This difference in load will bemeasured by the measuring systems 15 which control the device 16, as aconsequence of which the rod 14 is moved to the right. The result ofthis movement is that the right-hand guiding sheave 12 will swing to theright, whereby the higher elongation in the right-hand positioning wire11 will be compensated. The movement of the sheaves 12 may be effectedeither continuously or in one or more steps; it is also possible tocompensate by these movements the secondary actions of the wind force,such as the deflection of the stationary leg and the girder of thecontainer bridge.

Because the elongation in the positioning wires 11 is also dependent onthe length of these wires and because the angle of said wires to thevertical changes during hoisting and lowering, the load on the wires 11not only depends on the wind force on the container 9 but also on thedistance between the container 9 and the trolley 2. In order to takethis into account, a device (not shown) is provided which regulates themeasuring system 15 in conformity with the distance between the It isalso possible, as shown in FIG. 2 for each guiding sheave 12 to beadjusted independently. FIG. 2 illustrates only one of the sheaves 12,and the sheave is rotatably secured to the end of one of the arms of abellcrank lever, 17. The lever 17 is rotatably secured at its center toa frame 18, and the end of lever 17 remote from sheave 12 is connectedwith one end of a load measuring unit 19. The other end of unit 19 isengaged with a lever 20. The lever 20 is hinged at one end to the frame18 and is connected at its other end with an adjusting device 21, whichin the present embodiment comprises a hydraulic cylinder. When the loadmeasuring unit 19 records a difference in the load in the positioningwires 11, a signal is produced by which the adjusting device 21 isoperated in a manner so that the sheave 12 will swing in one directionor the other. If, for example, the load on the positioning wire 11,illustrated in FIG. 2, is higher than in the other positioning wire (notshown), then the adjusting device 21 will push the lever 20 down, as aresult of which the bellcrank lever 17 will swing counterclockwise andthe sheave 12 will move to the right.

It is, of course, also possible to put the adjusting device intooperation, starting from a measured displacement of the lifting frame 7of the container 9.

A second embodiment of the present invention is illustrated in FIG. 3,in which no separate positioning wires are employed. In FIG. 3, fourdrums 23 are mounted on a trolley 22, said drums being rigidly coupledto each other. The drums 23 may also be constructed as a single drum.Two hoisting cables 24 extend from each one of the drums 23 via guidingsheaves 25 to sheaves 28 mounted on the lifting frame 27, said liftingframe engaging container 26, said hoisting cables extending further topoints of attachment 29 on the trolley 22.

When the center of gravity of the container 26 is centrally located andno horizontal forces act on the container 26, all the hoisting cableshave an equal load. If a horizontal force, such as a wind force occursduring the positioning of the container 26 or if the center of gravityis offset, the eight hoisting cables are then subjected to differentloads and the container 26 will hang aslant as a consequence of thedifferences in elongation in the hoisting cables 24 caused by thedifferent loads. In order to compensate these differences in elongation,each point of attachment 29 comprises a load measuring device 30 (asshown in FIG. 4), which measures the rope tension. In response to thedifferences in force measured by the load measuring devices 30, a signalis produced by which a stepping motor 31 is operated. The stepping motor31 drives a transmission mechanism located in a casing 32 to cause alever 33 to be pivoted in one direction or the other. As a consequencethereof, the differences in elongation resulting from the load will becompensated, to prevent the container from tilting and movinghorizontally.

It is often desirable that during the travel of the trolley or thebridge, there is a possibility of swaying of the load. To this end, theguiding sheaves 25 are rotatably -mounted on the end of one of the armsof a bell-crank lever 34, as illustrated in FIG. 5. The lever 34 isrotatably supported in its center by a supporting means 35 mounted onthe trolley 22. A spring 36 is located between another supporting means(not shown) which is mounted on the trolley and the lever 34, so thatthe sheaves 25 may move when the load sways and the spring 36 will forma buffer. At the end of its other arm, the bell-crank lever 34 isconnected to a hydraulic cylinder 37, whose piston is connected to theframe 38 through a piston rod, the frame 38 being rigidly mounted on thetrolley 22. A hydraulic liquid is present on both sides of the piston inthe cylinder 37, the liquid being displaced from one side of the pistonto the other side via pipes 39 and 40 and an open blocking valve 41 as aconsequence of swaying of the lever 34. The pipes 39 and 40 extend to apump 42, and a valve 43 is mounted in the pipes, the valve 43 being inclosed position during the above mentioned operation, If swaying or anyeccentric position of the container is to be ruled out during thepositioning of the container, the blocking valve 41 is closed and thevalve 43 opened, as a result of which the piston in the cylinder 37 isdisplaced to a terminal position in which the bell-crank lever 34 cannotmove.

What is claimed is:

1. Apparatus for suspending a body, comprising a trolley, a single drummeans supported on said trolley, at least two pair of cables positivelyconnected to said single drum means and said body and each cable of eachpair extending at a substantial angle to the vertical and innon-parallel relation to the other cable of the pair and converging atsaid body, said drum means being drivable in rotation to cause saidcables to raise and lower the body respectively at the locations wherethe cables are connected to said body, a plurality of pivotal supportmembers mounted on the trolley, an equal plurality of sheaves each beingsupported on a respective support member for pivoting therewith, onecable passing on each sheave and being connected to the drum means andto the body, means .acting on said pivotal support members to move eachof the same and the respective sheaves supported thereby and meanscontrolling the last said means to operate the same and move theplurality of pivotable support members for cancelling any difference inelongation of the cables and thereby obviate any tilting or eccentricmovement of the body.

2. A device as claimed in claim 1 wherein said single drum meanscomprises a plurality of drums, a plurality of pairs of said cablesbeing provided for each drum, and a mechanical coupling means joiningsaid drums together for rotation as a common unit.

S TRIM LIN Patent No. ,986 Dated October 22; 1974 PRINTET- Inventor(s)Leonard Hupkes It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

On the cover sheet item 130] "1224/71" should read Signed and sealedthis 4th day of February 1.975.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner ofPatents FORM PO-10SOH0-69) USCOMM-DC 60376-P69 u.s. GOVERNMEN'Y PRINTINGOFFICE a n v cm

1. Apparatus for suspending a body, comprising a trolley, a single drummeans supported on said trolley, at least two pair of cables positivelyconnected to said single drum means and said body and each cable of eachpair extending at a substantial angle to the vertical and innon-Parallel relation to the other cable of the pair and converging atsaid body, said drum means being drivable in rotation to cause saidcables to raise and lower the body respectively at the locations wherethe cables are connected to said body, a plurality of pivotal supportmembers mounted on the trolley, an equal plurality of sheaves each beingsupported on a respective support member for pivoting therewith, onecable passing on each sheave and being connected to the drum means andto the body, means acting on said pivotal support members to move eachof the same and the respective sheaves supported thereby and meanscontrolling the last said means to operate the same and move theplurality of pivotable support members for cancelling any difference inelongation of the cables and thereby obviate any tilting or eccentricmovement of the body.
 2. A device as claimed in claim 1 wherein saidsingle drum means comprises a plurality of drums, a plurality of pairsof said cables being provided for each drum, and a mechanical couplingmeans joining said drums together for rotation as a common unit.